Chikungunya: a risk for Mediterranean countries?

The Italian outbreak of the 2007 summer and the active spreading of the Asian tiger mosquito Aedes albopictus in southern Europe, raise the possibility of local transmission of chikungunya (CHIK) in Mediterranean countries. Established in at least 12 countries in southern Europe since the end of the 1970s and in southern France since 2004, Ae. albopictus, is invading the French Mediterranean coast from East to West. To determine the possibility of an outbreak of CHIK in southern France, we provide an assessment of vector competence towards CHIK virus of different mosquito species, including Ae. albopictus, collected in 2006 in Camargue and the "Côte d'Azur" (Alpes Maritimes). In the laboratory, Ae. albopictus showed a high susceptibility to CHIK infection (77.1%) comparable to that observed for specimens collected in March 2006 in La Reunion Island. Hence, Ae. albopictus from southern France has the potential to serve as a vector based on its susceptibility to CHIK infection. Its presence in a tourist area such as the "Côte d'Azur" should be considered as a potential threat for the introduction of CHIK virus as in Italy where the initial case was probably a traveller coming back from an endemic zone.